Fast DDC

The RP2040 has the handy ability to boot as a USB storage device. You can then simply drag-drop a firmware file into the drive, and it will automatically restart with the new firmware running.

There are a few ways to boot as storage device:

• As long as it has no program running it will default to booting as storage device. For instance when coming straight from factory.

• Holding the BOOTSEL button when powering up.

• Using firmwareUploadMode() function, though this requires you to upload a firmware with this function first.

Community legend ZebbeBa has made several ready-to-use firmware files to drop onto your RP2040 boards. No coding required. Just chose the firmware that suits your needs and follow the wiring diagrams.

Naturally, these ready-to-use setups are generalized and aren't feature-packed. But they will do for most projects, and can help you get familiar with using DDC.

For firmwares using encoders there are different options for different types of encoders. You could try them all and see which one works the best.